1. Field of the Invention
The present invention relates to a slide fastener with the structure impervious to fluid, especially to a clamped type coupling element slide fastener with the structure impervious to fluid.
2. Description of Related Art
With respect to the status of the coupling element, a conventional waterproof slide fastener can be categorized into the single-side coupling element slide fastener and a clamped type coupling element slide fastener, the first one is the conventional nylon slide fastener, and the coupling element is a thick artificial mono-filament being heated for formation for forming as a spiral continuous coupling element then being sewed or woven for being combined on one surface at the inner edge of a support tape; the second one is the clamped type coupling element having various types of teeth, materials and process means for being combined with a support tape, e.g. a conventional metal slide fastener, a plastic molded slide fastener, a continuous teeth plastic molded slide fastener, a L-type nylon slide fastener, the characteristic is that the coupling elements are clamped with a sandwich-like means at the inner dual surfaces of the support tape, so each of the coupling elements is clamped on a first and a second surfaces at the inner edge of the support tape; wherein the coupling elements of the metal slide fastener are combined with the support tape with a riveting or punching means, and the coupling elements of the individual teeth plastic molded slide fastener are formed on the support tape through an injection molding means, and the continuous teeth plastic molded slide fastener and the L-type nylon slide fastener are combined with the support tape with a sewing means.
In the aforesaid waterproof clamped type coupling element slide fastener, the coupling elements and the support tape are symmetrically arranged, the symmetrical structure can prevent the transversal force from being increased because of leverage, so the central slit is prevented from being stretched due to the transversal force. The U.S. Pat. No. 7,181,810 has disclosed a conventional waterproof clamped type coupling element slide fastener, one layer of waterproof film is provided for covering the exterior of the clamped type coupling element and the support tape at the same surface for achieving the waterproof function; but in actual use, the waterproof film is located between two rigid units which are the coupling element and the slider, so the waterproof film would be continuously worn by the slider, especially the friction applied by the stop pin in the slider, the waterproof film is therefore worn out and damaged and the waterproof function is no longer provided.
In addition, the U.S. Pat. No. 2,746,113 and the U.S. Pat. No. 3,409,953 have disclosed that under the situation of the slide fastener being separated, a mold is utilized for enabling an impervious elastomeric member to be respectively covered at the exterior of the left and the right coupling elements, so when the slide fastener is coupled, the impervious elastomeric member would mutually squeeze for achieving the waterproof function. However, the impervious elastomeric member having a special shape would cause the slide fastener to be thicker and hardened, and a large friction force is generated inside the slider, so the arranging stability of the coupling elements inside the slider is altered, and a slider formed in a certain status is required for coupling the slide fastener, but the slider formed in a certain status often causes the arrangement of the coupling elements being poor and the coupling process not being smooth, thus the application of the waterproof slide fastener is very limited.
Moreover, the U.S. Pat. No. 2,557,163 has disclosed under the situation of two rows of coupling elements being separated, an impervious elastomeric member is respectively injection molded at the inner edge of a support tape, then the coupling elements are coupled for forming a waterproof slide fastener, during the impervious elastomeric member being injection molded, a space has to be reserved for accommodating the coupling elements, then the coupling elements are individually riveted, the above-mentioned process is very complicated so the application of the waterproof slide fastener is also very limited.